This invention relates to adjustable gas turbine exhaust nozzle for augmented turbo fan engines, and more particularly to the cooling of the nozzle convergent and divergent flaps and seals. In exhaust nozzles for augmented turbofan engines there is a variation of the nozzle cooling requirement depending on whether the engine is being operated in the augmented mode, partially augmented mode, or the nonaugmented mode.
The present invention automatically adjusts the air flow through the convergent flaps so that the required cooling is provided to the nozzle during all modes of nozzle operation. This adjustment is accomplished as a function of nozzle postiion and also as a function of the shape of the aft openings to the convergent flap.